Indeed, RG's automated algorithm has often problems with the identification of citations, but in many other cases it works well. We as users do not know on which factors this depends. You may be interested in using this method developed by Andrejs Krauklis : https://www.researchgate.net/post/Method_for_Improving_Recognition_of_Citations_References_on_ResearchGate/1. But you should apply this method before uploading the full text.